Array substrate, method of manufacturing the same and display apparatus having the same

ABSTRACT

A first wiring is formed on an array substrate, such that the first wiring has a first protrusion. A second wiring is formed on a different layer from that of the first wiring, such that a portion of the second wiring overlaps with the first protrusion. A protection layer that covers the first and second wirings is formed, such that the protection layer has first and second contact holes that expose the first and second wirings, respectively. Then, a third wiring that electrically connects the first wiring to the second wiring through the first and second contact holes is formed. When electrical connection between the first and second wirings is abnormal, a laser beam is irradiated toward the first protrusion, so that the electrical connection may be repaired.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relies for priority upon Korean Patent Application No.2003-48368 filed on Jul. 15, 2003, the contents of which are hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an array substrate, a method ofmanufacturing the array substrate and a display apparatus having thearray substrate. More particularly, the present invention relates to anarray substrate of which electrical contact between wirings isrepairable, a method of manufacturing the array substrate and a displayapparatus having the array substrate.

2. Description of the Related Art

Recently, a data driver IC and a gate driver IC (or scan driver IC) havebeen integrated on a liquid crystal display panel in order to reducemanufacturing cost and to meet market requirement of a narrow bezel. Inorder to acquire above integration, a scan driver circuit includingamorphous silicon thin film transistor (a-Si TFT) needs a simplestructure.

FIG. 1 is a diagram illustrating a conventional shift register. Theshift register in FIG. 1, for example, may be used for a liquid crystaldisplay apparatus.

Referring to FIG. 1, a scan driver circuit that generates a gate pulsefor activating a scan line includes a shift register. A unit stage ofthe shift register includes an S-R latch and an AND gate.

The S-R latch is activated based on a first input signal IN1 thatcorresponds to an output signal of a previous stage, and the S-R latchis inactivated based on a second input signal IN2 that corresponds to anoutput signal of a next stage. The AND gate generates a gate pulse (orscan signal) when the S-R latch is activated and clock is high.

In detail, first and second clocks CKV and CKVB applied to each unitstage for driving odd and even numbered scan lines have opposite phaseto each other.

The shift register in FIG. 1 may be formed and have a structure shown asin following FIG. 2.

FIG. 2 is a circuit diagram illustrating a unit stage in FIG. 1.

Referring to FIGS. 1 and 2, a unit stage of a shift register includes abuffer section 10, a charging section 20, a driving section 30 and adischarging section 40. The unit stage outputs a gate signal (or scansignal) based on a scan start signal STV or an output signal of aprevious stage.

In detail, the buffer section 10 includes a first transistor Q1 that hasgate and drain electrodes electrically connected to each other and asource electrode electrically connected to a first node N1. A firstinput signal IN1 is applied to the gate and drain electrodes of thefirst transistor Q1.

The charging section 20 includes a capacitor C. A first end of thecapacitor C is electrically connected to the first node N1. A second endof the capacitor C is electrically connected to the driving section 30.

The driving section 30 includes a second transistor Q2 and a thirdtransistor Q3. The second transistor Q2 includes a drain electrode thatis electrically connected to a clock terminal CK, a gate electrode thatis electrically connected to the first node N1, and a source electrodethat is electrically connected to the second end of the capacitor and anoutput terminal OUT. The third transistor Q3 includes a drain electrodethat is electrically connected to the source electrode of the secondtransistor Q2 and the capacitor C, and a source electrode that iselectrically connected to a first power voltage terminal VSS.

A first clock CKV or a second clock CKVB of which phase is opposite tothe first clock CKV is applied to the clock terminal CK.

The discharging section 40 includes a fourth transistor Q4. The fourthtransistor Q4 includes a drain electrode that is electrically connectedto the first node N1, a gate electrode that is electrically connected toa gate electrode of the third transistor Q3, and a source electrode thatis electrically connected to the first power voltage terminal VSS. Asecond input signal IN2 is applied to both of the gate terminals of thethird and fourth transistors Q3 and Q4.

When the first input signal IN1 is high, the capacitor C is electricallycharged. When the second input signal IN2 is high, the capacitor C iselectrically discharged. Therefore, S-R latch operation is performed.

When the capacitor C is electrically charged, the first or second clockCKV or CKVB that is applied to the clock terminal CK is outputtedthrough the second transistor Q2 that is turned on. Therefore, allswitching devices (or a-Si TFTs) that are electrically connected to theoutput terminal OUT are turned on. When the second input signal IN2 ishigh, the third transistor Q3 is turned on to pull down a voltage of theoutput terminal OUT to be equal to a first power voltage of the firstpower voltage terminal VSS.

Therefore, the first and second clocks CKV and CKVB, preferably, have ahigh voltage of about 15V in order to turn on the a-Si TFTs, and thefirst power voltage of the first power voltage terminal VSS preferablyhas a low voltage of about −7V in order to turn off the a-Si TFTs.

As described above, in order to output scan signal that activates theswitching devices formed in a display region, the shift registerrequires the first clock CKV or the second clock CKVB, and a first powervoltage that is applied to the first power voltage terminal VSS.

In order to apply the first or second clock CKV or CKVB and the firstpower voltage, a plurality of wirings and a plurality of contact regionsthat connect the wirings to the shift register are required.Additionally, in order to electrically connect transistors Q1, Q2, Q3and Q4 and capacitor C of the shift register with one another, aplurality of contact regions is formed.

When one of the contact regions is electrically opened, no signal isapplied to a scan line that corresponds to the contact region and scanlines disposed below the scan line that corresponds to the contactregion to induce defects. Therefore, display quality is deteriorated.

Furthermore, a large current flows through the wirings. Therefore, whenthe contact region is unstable, the contact region is easily opened. Inorder to repair such an opening of the contact region, separate wiringsfor a repair are required.

SUMMARY OF THE INVENTION

The present invention provides an array substrate of which electricalcontact between wirings is repairable.

The present invention also provides a method of manufacturing the arraysubstrate.

The present invention still also provides a display apparatus having thearray substrate.

In an exemplary array substrate according to the present invention, thearray substrate includes a substrate, a first wiring, a second wiring, aprotection layer and a third wiring. The first wiring having a firstprotrusion is formed on the substrate. The second wiring is formed on adifferent layer from that of the first wiring, such that a portion ofthe second wiring overlaps with the first protrusion. The protectionlayer covers the first and second wirings, and the protection layer hasfirst and second contact holes that expose the first and second wirings,respectively. The third wiring electrically connects the first wiring tothe second wiring through the first and second contact holes.

In an exemplary method of manufacturing an array substrate according tothe present invention, a first wiring is formed on the substrate, suchthat the first wiring has a first protrusion. A second wiring is formedon a different layer from that of the first wiring, such that a portionof the second wiring overlaps with the first protrusion. A protectionlayer that covers the first and second wirings is formed, such that theprotection layer has first and second contact holes that expose thefirst and second wirings, respectively. Then, a third wiring thatelectrically connects the first wiring to the second wiring through thefirst and second contact holes is formed.

In an exemplary display apparatus according to the present invention,the display apparatus includes an array substrate, a color filtersubstrate and a liquid crystal layer. The array substrate includes asubstrate, a first wiring, a second wiring, a protection layer and athird wiring. The first wiring is formed on the substrate, and the firstwiring has a first protrusion. The second wiring is formed on adifferent layer from that of the first wiring, such that a portion ofthe second wiring overlaps with the first protrusion. The protectionlayer covers the first and second wirings, and the protection layer hasfirst and second contact holes that expose the first and second wirings,respectively. The third wiring electrically connects the first wiring tothe second wiring through the first and second contact holes. The colorfilter substrate faces the array substrate, and the liquid crystal layeris interposed between the array substrate and the color filtersubstrate.

In another exemplary display apparatus according to the presentinvention, the display apparatus includes first, second and thirdwirings. The first wiring is disposed over a substrate, and the firstwiring is extended in a first direction. The second wiring is disposedover the substrate such that a portion of the second wiring overlapswith the first wiring, and the second wiring is extended in a seconddirection that is substantially perpendicular to the first direction.The third wiring electrically connects the first wiring to the secondwiring through a first contact hole that exposes the first wiring and asecond contact hole that exposes the second wiring.

Therefore, when an electrical connection between the first and secondwirings through the first contact hole is abnormal, a laser beam isirradiated toward the protrusion or overlapping region of the first andsecond wirings to electrically connect the first and second wirings.That is, the electrical connection between the first and second wiringsmay be repaired.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detailed exemplaryembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a diagram illustrating a conventional shift register;

FIG. 2 is a circuit diagram illustrating a unit stage in FIG. 1;

FIG. 3 is a schematic plan view illustrating a liquid crystal displayapparatus according to the present invention;

FIG. 4 is a block diagram illustrating a scan driving circuit employinga unit stage in FIG. 3;

FIG. 5 is a layout illustrating clock wirings for applying clocks to aunit stage of a shift register according to an exemplary embodiment ofthe present invention;

FIG. 6 is an enlarged view of X in FIG. 5;

FIGS. 7A to 7C are cross-sectional views taken along lines I-I′, II-II′and III and III′ in FIG. 6, respectively;

FIG. 8 is an enlarged view illustrating a region near contact holeaccording to another exemplary embodiment of the present invention;

FIG. 9 is an enlarged view illustrating a region near contact holeaccording to still another exemplary embodiment of the presentinvention; and

FIG. 10 is an enlarged view illustrating a region near contact holeaccording to further still another exemplary embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENTS

Hereinafter the embodiments of the present invention will be describedin detail with reference to the accompanied drawings.

FIG. 3 is a schematic plan view illustrating a liquid crystal displayapparatus according to the present invention. The liquid crystal displayapparatus in FIG. 3 corresponds to an array substrate of a-Si TFT liquidcrystal display apparatus.

Referring to FIG. 3, an array substrate includes a substrate 400, adisplay cell array circuit 410, a data driver circuit 420, data drivercircuit connection pads 422 and 424, a scan driver circuit 430, and ascan driver circuit connection pad 432. The display cell array circuit410, the data driver circuit 420, the data driver circuit connectionpads 422 and 424, the scan driver circuit 430 and the scan drivercircuit connection pad 432 are formed on the substrate 400 through aprocess of manufacturing a TFT. The scan driver circuit 430 correspondsto a shift register.

An integrated control and data driver chip 118 formed on a flexibleprinted circuit (FPC) 116 is electrically connected to circuits of thesubstrate 400, which are electrically connected to each other via theFPC 116. Therefore, a data signal, a data timing signal, a gate timingsignal and a data driver voltage are applied to the data driver circuit420 and the scan driver circuit 430 through the FPC 116.

The display cell array circuit 410 includes m-number of data lines DL1to DLm and n-number of scan lines GL1 to GLn. The data lines DL1 to DLmare extended in a longitudinal direction, and the scan lines GL1 to GLnare extended in a lateral direction.

A switching transistor ST is formed in a region defined by each of thedata lines DL1 to DLm and each of the scan lines GL1 to GLn. Theswitching transistor ST includes a source electrode that is electricallyconnected to one of the data lines DL1 to DLm, a gate electrode that iselectrically connected to one of the scan lines GL1 to GLn, and a drainelectrode that is electrically connected to a pixel electrode PE. Liquidcrystal LC is interposed between the pixel electrode PE and a commonelectrode CE formed on a color filter substrate.

When a pixel voltage is applied to the pixel electrode PE, electricfields are formed between the pixel electrode PE and the commonelectrode CE to adjust arrangement of the liquid crystal LC, therebycontrolling an amount of light to display gray scales.

The data driver circuit 420 includes a shift register 426 and n-numberof switching transistors SWT. n/8 number of the switching transistorsSWT are grouped to form 8 data line blocks BL1 to BL8.

n/8 input terminals of each of the data line blocks BL1 to BL8 areelectrically connected to the data driver circuit connection pad 424,and n/8 output terminals of each of the data line blocks BLI to BL8 areelectrically connected to n/8 data lines, respectively. Furthermore, oneof 8 output terminals of the shift register 426 is electricallyconnected to block selecting terminals.

Each of n-number of switching transistors SWT includes an a-Si TFThaving a source electrode that is electrically connected tocorresponding data line, a drain electrode that is electricallyconnected to corresponding input terminals of n/8 data input terminals,and a gate electrode that is electrically connected to the blockselecting terminal.

Therefore, n-number of data lines are divided into 8 blocks having n/8data lines. The shift register 426 selects 8 blocks based on a blockselection signal in sequence.

The shift register 426 receives a first clock CKH, a second clock CKHBand a block selection start signal STH through the data driver circuitconnection pad 422. Output terminals of the shift register 426 areelectrically connected to the block selection signal of correspondingline blocks.

FIG. 4 is a block diagram illustrating a scan driving circuit employinga unit stage in FIG. 3. The shift register in FIG. 4 corresponds to ashift register of a scan driver circuit.

Referring to FIG. 4, a scan driver circuit according to the presentinvention includes a shift register. The shift register includes aplurality of stages SRC1, SRC2, . . . SRCN, SRCD. An output terminal OUTof one stage is electrically connected to a first input terminal IN1 ofa next stage. The stages SRC1, SRC2, . . . SRCN correspond to scanlines, and the stage SRCD is a dummy stage. Each stage includes firstand second input terminals IN1 and IN2, an output terminal OUT, firstand second clock input terminals CKV1 and CKV2, and a first powervoltage terminal VSS.

The first stage SRC1 receives a scan start signal STV through the firstinput terminal IN1. The scan start signal STV is a pulse that isoutputted from an external device such as a graphic controller andsynchronized with a vertical synchronization signal Vsync.

Output signals of each of the stages SRC1, SRC2, . . . SRCN are appliedto each scan line of the array substrate having a plurality of TFTs.

Odd numbered stages SRC1, SRC3, . . . , SRCN-1 receive a first clock CKVthrough the first clock input terminal CKV1, and the odd numbered stagesSRC1, SRC3, . . . , SRCN-1 receive a second clock CKVB through thesecond clock input terminal CKV2.

Even numbered stages SRC2, SRC4, . . . , SRCN receive the second clockCKVB through the first clock input terminal CKV1, and the even numberedstages SRC2, SRC4, . . ., SRCN receive the first clock CKV through thesecond clock input terminal CKV2. A phase of the first clock CKV isopposite to a phase of the second clock CKVB. A duty cycle of the firstand second clocks CKV and CKVB is about 16.6 ms.

The stages SRC1, SRC2, . . . , SRCN receive output signals G2, G3, . .., GN and GD of the stages SRC2, SRC3, . . . , SRCD as a control signalthrough the second input terminal IN2, respectively. Therefore, thecontrol signal applied to the second input terminal IN2 is delayed.

Each stage outputs a high signal in sequence to select a scan line.

The last stage SRCN requires a control signal that is to be inputted tothe second input terminal IN2, so that the dummy stage SRCD provides thelast stage SRCN with the dummy signal GD.

Hereinbefore, a phase of the first clock CKV is opposite to a phase ofthe second clock CKVB. Alternatively, a phase difference between thefirst and second clocks CKV and CKVB may be 90° or 270°.

Additionally, hereinbefore, the stages may be grouped into a first groupto which the first clock is provided and a second group to which thesecond clock is provided. Alternatively, the stages may be grouped intoequal to or greater than three groups to which equal to or greater thanthree clocks are applied, respectively.

FIG. 5 is a layout illustrating clock wirings for applying clocks to aunit stage of a shift register according to an exemplary embodiment ofthe present invention.

Referring to FIG. 5, a plurality of wirings such as a first powervoltage wiring VSS1, a first clock wiring CKV1, a second clock wiringCKVB1, a scan start wiring STV, etc., is disposed at outside region of ashift register having a plurality of unit stages, such that the firstpower voltage wiring VSS1, the first clock wiring CKV1, the second clockwiring CKVB1 and the scan start wiring STV are substantially parallelwith each other. The narrower a width of the wirings is, the farther isa distance between the wirings and the shift register.

In detail, the scan start signal wiring STV of which width is thenarrowest is adjacent to the shift register, the second and first clockwirings CKVB1 and CKV1 are adjacent to the scan start wiring STV, andthe first power voltage wiring VSS1 of which width is the widest isadjacent to the first clock wirings CKV1.

Additionally, a repair wiring REPAIR, a second common voltage wiringVCOM2 and a first common voltage wiring VCOM1 are disposed adjacent tothe first power voltage wiring in that order. The repair wiring REPAIR,the second common voltage wiring VCOM2 and the first common voltagewiring VCOM1 are longitudinally and parallelly extended. The repairwiring REPAIR may not be formed in order to reduce an area on whichwirings are formed.

In order to compensate RC-delay caused by the first and second clockwirings CKV1 and CKVB1 that are disposed at a right side of the firstpower voltage wiring VSS1, a third clock wiring CKV2 that transmits thefirst clock and a fourth clock wiring CKVB2 that transmits the secondclock are formed at a left side of the first power voltage wiring VSS1.

In FIG. 5, each of the wirings STV, CKVB1, CKV1, VSS1, CKV, CKVB2,REPAIR, VCOM2 and VCOM1 that are extended in a longitudinal direction iselectrically connected to the shift register formed at a right sidethrough connection wirings CKV3, CKVB3 and VSS2 that are extended in alongitudinal direction to provide the shift register with power voltagesor clocks.

The wirings STV, CKVB1, CKV1, VSS1, CKV, CKVB2, REPAIR, VCOM2 and VCOM1and the connection wirings CKV3, CKVB3 and VSS2 are formed on adifferent layer. Therefore, the wirings STV, CKVB1, CKV1, VSS1, CKV,CKVB2, REPAIR, VCOM2 and VCOM1 are electrically connected to theconnection wirings CKV3, CKVB3 and VSS2 through contact holes CNT1,CNT2, CNT3, CNT4, CNT5 and CNT6. A portion of the wirings STV, CKVB1,CKV1, VSS1, CKV, CKVB2, REPAIR, VCOM2 or VCOM1 overlaps with theconnection wirings CKV3, CKVB3 and VSS2. Therefore, when one of thecontact holes CNT1, CNT2, CNT3, CNT4, CNT5 and CNT6 is electricallyopened, a laser beam may be irradiated onto the overlapping portion toelectrically connect the wirings STV, CKVB1, CKV1, VSS1, CKV, CKVB2,REPAIR, VCOM2 or VCOM1 to the connection wirings CKV3, CKVB3 and VSS2.Therefore, defects may be repaired.

Then, the first power voltage wiring VSS1 and the connection wiringdisposed over the first power voltage wiring VSS1, and overlapping withthe first power voltage wiring VSS1, for example, will be explained indetail.

FIG. 6 is an enlarged view of X in FIG. 5, and FIGS. 7A to 7C arecross-sectional views taken along lines I-I′, II-II′ and III and III′ inFIG. 6, respectively.

Referring to FIGS. 6 to 7C, a first power voltage wiring VSS1 having athickness of about 500 angstroms is formed, such that the first powervoltage wiring VSS1 is extended in a first direction, for example alongitudinal direction. The first power voltage wiring VSS1 includes afirst protrusion P1 formed near a region at which first and secondcontact holes CNT1 and CNT2 are to be formed. The first power voltagewiring VSS1 is patterned from a same layer as that of a gate wiring anda gate electrode.

Then, an active layer ACT is formed on the first power voltage wiringVSS1, and a first connection wiring VSS2 having a thickness of about3000 angstroms is formed on the active layer ACT. The second connectionwiring VSS2 is extended in a second direction, for example a lateraldirection. The first connection wiring VSS2 includes a second protrusionP2 formed near a region at which first and second contact holes CNT1 andCNT2 are to be formed. The second protrusion P2 is opposite to the firstprotrusion P1 with respect to the first contact hole CNT1. Therefore,when an electrically connection between the first power voltage wiringVSS1 and the first connection wiring VSS2 through the first contact holeCNT1 is abnormal, a position of the first and second protrusions P1 andP2 may be easily detected. The first connection wiring VSS2 is patternedfrom a same layer as that of a source electrode and a drain electrode.

In FIGS. 6 to 7C, the first power voltage wiring VSS1 and the firstconnection wiring VSS2 overlap each other two times by the first andsecond protrusions P1 and P2. However, the first power voltage wiringVSS1 and the first connection wiring VSS2 overlap each other only onceby only one protrusion, or the first power voltage wiring VSS1 and thefirst connection wiring VSS2 overlap each other more than or equal tothree times by more than or equal to three protrusions.

The first connection wiring VSS2 may include only one layer.Alternatively, the first connection wiring VSS2 may include a firstlayer including aluminum (Al) and a second layer including chromium(Cr). The first layer has a thickness of about 2500 angstroms, and thesecond layer has a thickness of about 500 angstroms. The second layer isdisposed on the first layer.

A portion of the active layer ACT, which is disposed under the firstconnection wiring VSS2, may not be removed. The active layer ACTdisposed below the first connection wiring VSS2 functions as a channellayer of the thin film transistor employed by a unit stage of the shiftregister.

As described above, a portion of the first power voltage wiring VSS1,which is near the first and second contact holes CNT1 and CNT2, isprotruded to form the first protrusion P1 in order to overlap with thefirst connection wiring VSS2. A portion of the first connection wiringVSS2, which is near the first and second contact holes CNT1 and CNT2, isprotruded to form the second protrusion P2 in order to overlap with thefirst power voltage wiring VSS1.

A protection layer PAS covers the first power voltage wiring VSS1 andthe first connection wiring VSS2 formed on the substrate 400. However,the protection layer PAS exposes a portion of the first power voltagewiring VSS1, which is near the first contact hole CNT1, and a portion ofthe first connection wiring VSS2, which is near the second contact holeCNT2.

A first connection electrode CNE1 having a thickness of about 500angstroms is formed on the protection layer PAS. The first connectionelectrode CNE1 may include indium tin oxide (ITO), indium zinc oxide(IZO), etc. The first connection electrode CNE1 electrically connectsthe first power voltage wiring VSS1 and the first connection wiring VSS2through the first and second contact holes CNT1 and CNT2.

When the first power voltage wiring VSS1 has a thickness of about 500angstroms, the first connection wiring VSS2 has a thickness of about3000 angstroms, and the first connection electrode CNE1 has a thicknessof about 500 angstroms, reparability is most effective. However, thethickness does not limit the scope of the present invention.

In FIG. 6, an edge of the first power voltage wiring VSS1, which isexposed through the first contact hole CNT1, is straight. However, heatsare generated more at an edge region of the first power voltage wiringVSS1 than at a center region of the first power voltage wiring VSS1.Additionally, a contact resistance is higher at the edge region of thefirst power voltage wiring VSS1 than at the center region of the firstpower voltage wiring VSS1. Therefore, a contact area is increased asshown in FIG. 8.

FIG. 8 is an enlarged view illustrating a region near contact holeaccording to another exemplary embodiment of the present invention. Inthe present embodiment, the shape of the region near contact holeaccording to the present embodiment is same as that of FIG. 6 except forthe first power voltage wiring. Thus, any further explanation will beomitted.

Referring to FIG. 8, the first power voltage wiring VSS11 has a uniformwidth except for a seventh contact hole CNT7. That is, the first powervoltage wiring VSS11 has a rugged edge formed in the seventh contacthole CNT7. Therefore, a heat generated from the seventh contact holeCNT7 is reduced by increasing an electrical contact region.

FIG. 9 is an enlarged view illustrating a region near contact holeaccording to still another exemplary embodiment of the present inventionand FIG. 10 is an enlarged view illustrating a region near contact holeaccording to further still another exemplary embodiment of the presentinvention.

The inventions of FIGS. 9 and 10 are same as the invention of FIG. 8except for seventh contact holes CNT7 a and CNT7 b and eighth contactholes CNT8 a and CNT8 b. Thus, the same reference numerals will be usedto refer to the same or like parts as those described in FIG. 8 and anyfurther explanation will be omitted.

Referring to FIGS. 9 and 10, the seventh contact holes CNT7 a and CNT7 band the eight contact holes CNT8 a and CNT8 b have a contour includingconcave and convex curves that are disposed alternately. Therefore, acontact resistance in the contact holes may be reduced.

Hereinbefore, a structure of a contact region of the power voltagewiring and the clock wiring has been explained. Alternatively, thestructure may be applied to a contact region between TFTs of a unitstage of the shift register.

The structure of the contact region may be applied to a contact regionbetween unit stages of the shift register.

That is, the present invention may be applied to all contact holes thatconnect a first layer and a second layer disposed on different layerfrom the first layer.

Having described the exemplary embodiments of the present invention andits advantages, it is noted that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by appended claims.

1. An array substrate comprising: a substrate; a first wiring formed asa layer on the substrate and extended in a first direction, the firstwiring having a first protrusion of a reduced width; a second wiringformed as a different layer on the substrate from the layer of the firstwiring and extended in a second direction that is substantiallyperpendicular to the first direction, wherein a portion of the secondwiring overlaps a portion of the first protrusion; a protection layercovering the first and second wirings, the protection layer having firstand second contact holes that expose the first and second wirings,respectively; and a third wiring that electrically connects the firstwiring to the second wiring through the first and second contact holes,wherein the first wiring further comprises a rugged edge, and the ruggededge is formed in the first contact hole.
 2. The array substrate ofclaim 1, wherein a portion of the protection layer, which is disposedover the first protrusion, is adapted to be removed by irradiation of alaser beam thereon, so that the third wiring can electrically connectthe first wiring to the second wiring.
 3. The array substrate of claim1, wherein the first protrusion is adjacent to the first contact hole.4. The array substrate of claim 1, wherein the second wiring comprises asecond protrusion, a portion of which overlaps a portion of the firstwiring.
 5. The array substrate of claim 4, wherein the second protrusionis oppositely disposed to the first protrusion with respect to the firstcontact hole.
 6. The array substrate of claim 1, wherein a contour ofthe first contact hole comprises concave and convex curves that aredisposed alternately.
 7. The array substrate of claim 1, whereincontours of the first and second contact holes comprise concave andconvex curves that are disposed alternately.
 8. The array substrate ofclaim 1, wherein the substrate comprises an amorphous silicongate-driver.
 9. A method of manufacturing an array substrate,comprising: forming a first wiring which is extended in a firstdirection as a layer on the substrate, such that the first wiring has afirst protrusion of a reduced width; forming a second wiring which isextended in a second direction substantially perpendicular to the firstdirection as a different layer on the substrate from that of the firstwiring, such that a portion of the second wiring overlaps a portion ofthe first protrusion; forming a protection layer that covers the firstand second wirings, the protection layer having first and second contactholes that expose the first and second wirings, respectively; andforming a third wiring that electrically connects the first wiring tothe second wiring through the first and second contact holes, whereinforming the first wiring includes forming the first wiring with a ruggededge and forming the rugged edge in the first contact hole.
 10. Themethod of claim 9, wherein a portion of the protection layer, which isdisposed over the first protrusion, is adapted to be removed when byirradiation of a laser beam thereon, so that the third wiring canelectrically connect the first wiring to the second wiring.
 11. Themethod of claim 9, wherein the first protrusion is adjacent to the firstcontact hole.
 12. The method of claim 9, wherein the second wiringcomprises a second protrusion, a portion of which overlaps a portion ofthe first wiring.
 13. The method of claim 12, wherein the secondprotrusion is oppositely disposed to the first protrusion with respectto the first contact hole.
 14. The method of claim 9, wherein a contourof the first contact hole comprises concave and convex curves that aredisposed alternately.
 15. The method of claim 9, wherein contours of thefirst and second contact holes comprise concave and convex curves thatare disposed alternately.
 16. A display apparatus comprising: an arraysubstrate comprising; a substrate; a first wiring formed as a layer onthe substrate and extended in a first direction, the first wiring havinga first protrusion of a reduced width; a second wiring formed as adifferent layer on the substrate from that of the first wiring andextended in a second direction that is substantially perpendicular tothe first direction, such that a portion of the second wiring overlaps aportion of the first protrusion; a protection layer covering the firstand second wirings the protection layer having first and second contactholes that expose the first and second wirings, respectively; and athird wiring that electrically connects the first wiring to the secondwiring through the first and second contact holes; a color filtersubstrate that faces the array substrate; and a liquid crystal layerinterposed between the array substrate and the color filter substrate,wherein the first wiring further comprises a rugged edge, and the ruggededge is formed in the first contact hole.
 17. The display apparatus ofclaim 16, wherein a portion of the protection layer, which is disposedover the first protrusion, is adapted to be removed by irradiation of alaser beam thereon, so that the third wiring can electrically connectthe first wiring to the second wiring.
 18. The display apparatus ofclaim 16, wherein the first protrusion is adjacent to the first contacthole.
 19. The display apparatus of claim 16, wherein the second wiringcomprises a second protrusion that overlaps with the first wiring. 20.The display apparatus of claim 19, wherein the second protrusion isoppositely disposed to the first protrusion with respect to the firstcontact hole.
 21. The display apparatus of claim 16, wherein a contourof the first contact hole comprises concave and convex curves that aredisposed alternately.
 22. The display apparatus of claim 16, whereincontours of the first and second contact holes comprise concave andconvex curves that are disposed alternately.
 23. A display apparatuscomprising: a first wiring disposed as a layer over a substrate, whereinthe first wiring is extended in a first direction and has a firstprotrusion of a reduced width; a second wiring disposed as a differentlayer over the substrate such that a portion of the second wiringoverlaps a portion of the first protrusion, the second wiring beingextended in a second direction that is substantially perpendicular tothe first direction; and a third wiring that electrically connects thefirst wiring to the second wiring through a first contact hole thatexposes the first wiring and a second contact hole that exposes thesecond wiring, wherein the first wiring further comprises a rugged edge,and the rugged edge is formed in the first contact hole.
 24. The displayapparatus of claim 23, wherein the substrate comprises a display regionincluding a plurality of scan lines and a plurality of data lines, and aperipheral region including a scan driver circuit that outputs a signalfor activating the scan lines, and the first, second and third wirings.25. The display apparatus of claim 24, wherein the scan driver circuitcomprises a shift register.
 26. The display apparatus of claim 24,wherein a first clock is transferred to the scan driver circuit throughthe first wiring, and a second clock having different phase from that ofthe first clock is transferred to the scan driver circuit through thesecond wiring.
 27. The display apparatus of claim 24, wherein the datalines are extended in the first direction and the scan lines areextended in the second direction.
 28. The display apparatus of claim 23,further comprising a protection layer having the first and secondcontact holes, the protection layer being disposed between the first andsecond wirings.
 29. The display apparatus of claim 28, wherein a portionof the protection layer is adapted to be removed by irradiation of alaser beam onto an overlapping region of the first and second wirings,so that the third wiring can electrically connect the first wiring tothe second wiring.
 30. The display apparatus of claim 23, wherein anoverlapping region of the first and second wirings is adjacent to thefirst or second contact hole.
 31. The display apparatus of claim 23wherein a contour of the first contact hole comprises concave and convexcurves that are dispose alternately.
 32. The display apparatus of claim23, wherein contours of the first and second contact holes compriseconcave and convex curves that are disposed alternately.
 33. An arraysubstrate comprising: a substrate; a first wiring formed as a layer onthe substrate and extended in a first direction, the first wiring havinga first protrusion of a reduced width; a second wiring formed as adifferent layer on the substrate from the layer of the first wiring andextended in a second direction that is substantially perpendicular tothe first direction, wherein a portion of the second wiring overlaps aportion of the first protrusion; a protection layer covering the firstand second wirings, the protection layer having first and second contactholes that expose the first and second wirings, respectively; and athird wiring that electrically connects the first wiring to the secondwiring through the first and second contact holes, wherein the firstprotrusion is separated from the first contact hole.
 34. The arraysubstrate of claim 33, wherein a portion of the protection layer, whichis disposed over the first protrusion, is adapted to be removed byirradiation of a laser beam thereon, so that the third wiring canelectrically connect the first wiring to the second wiring.
 35. Thearray substrate of claim 33, wherein the second wiring comprises asecond protrusion, a portion of which overlaps a portion of the firstwiring.
 36. The array substrate of claim 35, wherein the secondprotrusion is oppositely disposed to the first protrusion with respectto the first contact hole.
 37. The array substrate of claim 33, whereina contour of the first contact hole comprises concave and convex curvesthat are disposed alternately.
 38. The array substrate of claim 33,wherein contours of the first and second contact holes comprise concaveand convex curves that are disposed alternately.
 39. An array substratecomprising: a substrate; first wiring formed as a layer on the substrateand extended in a first direction; a second wiring formed as a differentlayer on the substrate from the layer of the first wiring and extendedin a second direction that is substantially perpendicular to the firstdirection, wherein an end portion of the second wiring includes a firstend portion with a widened width and a second end portion with a reducedwidth, the second end portion protruding from the first end portion andpartially overlapping the first wiring; a protection layer covering thefirst and second wirings, the protection layer having a first contacthole that exposes a boundary portion of the first wiring and a secondcontact hole that exposes the second wiring; and a third wiring thatelectrically connects the first wiring to the second wiring through thefirst and second contact holes.
 40. The array substrate of claim 39,wherein the first wiring comprises a first protrusion with a reducedwidth.
 41. The array substrate of claim 40, wherein a portion of theprotection layer, which is disposed over the first protrusion, isadapted to be removed by irradiation of a laser beam thereon, so thatthe third wiring can electrically connect the first wiring to the secondwiring.
 42. The array substrate of claim 40, wherein the firstprotrusion is adjacent to the first contact hole.
 43. The arraysubstrate of claim 41, wherein the second end portion is oppositelydisposed to the first protrusion with respect to the first contact hole.44. The array substrate of claim 39, wherein a contour of the firstcontact hole comprises concave and convex curves that are disposedalternately.
 45. The array substrate of claim 39, wherein contours ofthe first and second contact holes comprise concave and convex curvesthat are disposed alternately.